Implementation of this is only to provide developers a tool to deal with the urltoken encoded by a base64 variant from Microsoft in their .Net framework HttpServerUtility.UrlTokenEncode
for now only string is supported
var urltoken = require('urltoken');
var encoded = urltoken.encode(origin_str);var urltoken = require('urltoken');
var decoded = urltoken.decode(encoded_str, 'utf8'); // the second optional argument is the encoding for decode the base64 string to human-readable text. if omitted, utf8 will be used